Permanent magnet rotating electric machines are known as rotating electric machines, such as electric motors and generators. The permanent magnet rotating electric machine includes a rotor having a plurality of permanent magnets arranged in a circumferential direction of a rotor core and a stator disposed so as to face an outer peripheral surface of the rotor with an air gap defined therebetween.
The rotating electric machines of this type include a surface permanent magnet (SPM) rotating electric machine having a permanent magnet disposed relative to an outer peripheral surface of the rotor core and an interior permanent magnet (IPM) rotating electric machine having a permanent magnet embedded in an inside of the rotor core. The IPM rotating electric machine is widely used particularly in the field of, for example, machine tools, electric vehicles, and robots.